To meet Federal Motor Vehicle Safety Standards, a vehicle may include an upper anchor attachment to receive a child safety seat tether hook connected to an upper portion of the child safety seat back. The connection of the upper portion of the child safety seat to the vehicle may reduce the forward movement of the child safety seat during a frontal crash. However, the shock applied by child safety seat restraining equipment to the child safety seat occupant may increase in case of a forward vehicle collision.
One approach to reduce the impact of the collision force to the child safety seat is described in the U.S. Pat. No. 6,767,057. In particular, anchor attachments to the child safety seat with energy absorbing mechanism are disclosed. In one example, the upper anchorage assembly includes a steel U-shaped bracket with a first end secured to the vehicle horizontally and a second end having a latchable portion for releasable engagement with the corresponding upper child seat latch. If the predetermined forward force is exceeded, the U-shaped bracket bends forward and is deformed. The deformation of the bracket absorbs energy. In another example for a lower anchorage assembly, the U.S. Pat. No. 6,767,057 discloses a C-shaped steel bracket with two legs having corrugated pleats and a through-hole at the free end. A steel anchor post extends between the two legs of the attachment bracket through the through-holes and is welded to the bracket. If the predetermined extension force on the pleats is exceeded, the pleats are straightened. As the metal yields and straightens each pleat, energy is absorbed.
However, the inventors herein have recognized disadvantages with such energy absorbing devices. For example, the ability of absorbing energy of the above devices can be limited by the length of the U-shaped plate and the corrugated pleats, which in turn can be restricted by the available space for the anchor attachment. Further, since one end of the anchorage assembly is fixed to the vehicle and the deformation occurs mainly in one direction, the devices may reduce the impact force in this direction while the reduction on the impact force in another direction may be limited. Furthermore, the disclosed upper anchorage assembly may be observed to be obtrusive in appearance due to its shapes.